Amplifier circuits with double control



June 1949- J. L: H. JONKER ETAL 7 5 AMPLIFIER CIRCUITS WITH DOUBLE CONTROL FiledMay 9, 1946 I -|NVENTCRS JOHAN LODEWIJK HENDRIK JONKER 8| PETRUS HUBERTUS JOHANNES AGNES KLEYNEN BY I ATTORNEY,

Patented June 21, 1949 AMPLIFIER CIRCUITS WITH DOUBLE CONTROL Johan Lodewijk Hendrik J onker and Petrus Hubertus Johannes Agnes Kleynen, Eindhoven, Netherlands, assignors, by mesne assignments, to Hartford National Bank and Trust Company, Hartford, Conn, as trustee Application May 9, 1946, Serial No. 668,550

In the Netherlands July 19, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires July 19, 19,61.

5 Claims. (01. 179-171 The invention relates to amplifiers circuits comprising an electric discharge tube with double control, one of the controls being efiected with the aid of deflection members. The term control is to be understood to mean not only the normal control by an incoming signal but also the application of a variable biassing potential for volume control and the like.

Amplifier circuits in which two control voltages act upon two control grids of a discharge tube are known. A known example of such a tube is the so-called control hexode. These tubes entail the drawback that an important reaction of the second control space on the first takes place and through this reaction the proper operation of the tube is afiected. If one of the control grids is replaced by a deflection control system, other diificulties occur since deflection control in itself is highly insensitive. In fact, if use is made of deflection plates which are maintained at a negative potential, a very high space charge occurs.

Thepresence of the space charge results in unsharp beams occurring, while in some cases also a reaction may take place. If the deflection plates are made positive, the beams are sharper, it is true, but the sensitivity is lower due to greater electron speed.

Applicant has found that these drawbacks may be obviated with the aid of a circuit and a tube according to the present invention. This circuit comprises a discharge tube with double control systems in which one of the control systems, preferably the second, is a deflection system and at least one of the deflection plates has supplied to it a control voltage obtained by amplification of a voltage supplied to the grid of the tube.

When using this circuit it is possible to obviate on the one hand the difliculties which occur by the return of electrons to the first control space, whereas on the other hand the sensitivity considerably increases and one of the deflection elements may be connected without objection to a point of positive voltage.

The amplified control voltage to be supplied to the deflection means may be derived from an impedance included in the anode circuit or in the screen-grid circuit of another amplifying tube contained in the apparatus.

According to one particular embodiment of the present invention, however, this control voltage is taken from the screen grid of the tube in which the two controls take place and in which the screen-grid conductor includes an impedance across which the amplified control voltage occurs. This impedance may be constituted by a i 2 a resistance which is by-passed for the signal frequency so that the deflection means have solely supplied to them a variable direct voltage for volume control or the like.

According to another embodiment, one of the deflection members is connected in the abovedescribed manner to the screen grid of the tube and the other member to the control grid. Thelatter deflection member may, however, also be connected to a point of fixed positive or negative potential.

nal frequency by a condenser.

The invention will be explained more fully by reference to the accompanying drawing showing, by way of example, a circuit and a tube according to the invention.

In the figure, l indicates an electric discharge tube containing a cathode 2, a control grid 3, a screen grid 4, an anode 5 and two deflection plates 6 and l. The tube contains in addition a. plate 8, which is preferably connected to the anode and serves for an advantageous electron distribution in accordance with the anode po tential, and a body 9, preferably in the form of a rod, which is at low potential and prevents troublesome secondary emission phenomena between the anode and the positive deflection plate.- As can be seen from the drawing, a control voltage for volume'control, together with the incoming signal, is impressed on the control grid 1 3 via the circuit I II. The screen grid is connected to the deflection plate (via the conductor II and the screen-grid conductor includes a resistance I2 between the screen grid and the source of supply I3, which resistance is by-passed for the sig- The deflection plate 6 is also connected to the control grid via the circuit 10. The anode lead includes in addition the output circuit l4 and the cathode lead includes the parallel connection I5 of a resistance and a condenser which serves to generate the desired fixed grid biassing potential.

We claim:

1. An amplifier circuit arrangement, comprsing an electron discharge tube having an electronemitting cathode, a control grid, a screen grid, an electron beam deflection system comprising a first deflection electrode, a second deflection electrode arranged in cooperative association with said first deflection electrode and an anode, means to couplesaid first deflection electrode to the grid of saidtube, means to connect said second deflection electrode to said screen grid, means to apply operating potentials to said tube, means to apply a signal voltage to the control grid of said tube,

and an output load impedance means connected to said anode- 2.; An amplifier circuit arrangement, comprising anelectron discharge tube having an electronemitting cathode, a control grid, a screen grid, an

electron beam deflection system comprising acircuit said resistor for currents of frequency of said signal voltage, means to apply operating potentials to said tube, means to apply a. signal voltage to the control grid of said tube, and an output load impedance means connected to said anode.

3. An amplifier circuit arrangement, comprising an electron discharge tube having an electronemittingcathode, a control grid, a screen grid, an electron beam deflection system comprising a first deflection electrode, second and third deflection electrodes arranged in cooperative association withsaid first deflection electrode, an anode and a secondary emission counteracting member arranged between said second deflection electrode and said anode, a cathode resistor interposed in the cathode circuit of said tube, means to couple said first deflection electrode to the control grid of said tube, means'toconnect said second deflectionelectrode to said screen grid, means to connect said third deflection electrode to said anode, a second resistor connected to said screen grid, means to-short' circuit said resistor for currents of frequency of said signal voltage, means to apply operating potentials between said cathoderesistor and said anode and said second resistor, means to apply a signal voltage to the control grid of saidtube, and a resonant circuit connected to said anode.

4. An amplifier circuit arrangement, comprising'an electron dischargetube having an electronemitting cathode, a control grid, a screen grid, an electron beam deflectionsystem comprising a first deflection electrode, second and. third de-- flection electrodes arranged in cooperative asso ciationwith said first deflection electrode, an anode and a secondary emission counteracting member arranged between said second deflection electrode; and said anode, a firstiresonant. circuitv interposed between the grid and the: cathode; of said tube, a cathode: resistor interposed in: the cathode circuit oi said tube, means to connect said first deflection electrode to said firstresonant circuit, means to connect said. second deflection electrode. to said screen grid, means to connect said third deflection electrode to said anode, a second resistor connected to said screen grid, means to short circuit said resistor for currents of frequency of said signal voltage, means to apply operating potentials between said cathode resistor and the anode. of said tube and said second resistor, means to apply a signal voltage between said cathode resistor and said first resonant circuit, and a second resonant circuit connected to said anode to produce an output signal voltage.

An amplifier circuit arrangement, comprising anelectron discharge tube having an electronemitting cathode, a control grid, a screen grid, an electronbeam deflection system comprisin a first deflection electrode, a second deflection electrode and a third. deflection electrode arranged in cooperative association with said first deflection electrode, an anode and a secondary emission counteracting member arranged between said second deflection electrode and said anode, said tln' rd deflection electrode being connected to said anode, means to connect said second deflection electrode to said screen grid, a first resonant circuithaving one terminal thereof connected to the of said tube, a cathode resistor having one terminal thereof connected to the cathode of said tube, a capacitor coupling the remaining terminals of said resonant first circuit and said cathode resistor, means to connect said first deflectiorr electrode to the remaining terminal of said first resonant circuit, a second resonant ciredit having one terminal thereof connected to said anode, a resistor connected between said screen; grid and the remaining terminalv of said second resonant circuit, means to apply operating potentials to said remaining terminals of said cathode. resistor and said second resonant circuit, means to apply a signal voltage between saidremaining terminals of said cathode resistor and said first resonant circuit, and a capacitor coupll'ng said screen grid to said cathode, said ca paci'tor having a slow reactance value for voltages of'thefrequency of said signal voltage.

JOHAN LODEWIJK HENDRIK J ONKER.

HUBERTUS J OI-LANNES AGNES REFERENCES; CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,159,818 Pl'aistowe et al May 23, 1939 2,205,069 Rust June 18, 1940 2,214,614. Hunt Sept. 10, 1940 2,219,902 Myerset al Oct. 29, 1940 2,227,020 Schlesinger Dec. 31, I940 

